You are only seeing the doghouse on the last leg of your route because of your current GPS position relative to the earlier legs. Once you pass a leg, its doghouse will no longer appear.
If your GPS location is ahead of the legs where the doghouses seem to be missing, the app assumes you have already flown those portions of the route and does not display them. You can test this by temporarily disabling Aero App’s access to location services on your device, then closing and reopening the app. After doing so, all doghouses for each leg of the route should appear.